Jeffrey Toobin, who covers law for The New Yorker, has been everywhere talking about his Harvard Law classmate Elena Kagan. But sources say he exaggerates their closeness. “They were only in study groups together. They weren’t friends. Yet he now goes on TV every night yammering on about her,” said one source. The married Toobin — who kept a low profile after having an out-of-wedlock son with Casey Greenfield last year — launched a come back when Kagan was picked for the US Supreme Court. “She kept to herself,” Toobin said the other night on CNN. “All of her actual friends say the opposite,” said our source.